(Os, 8) [lix 
that a slight odour is present. I find also a faint scent in the 
scales of the upper surface of Gonepteryx rhamni, ¢, which I 
cannot describe further than by calling it ‘ flowery.’ 
“There is, I think, absolutely no doubt that the scent of 
the male butterflies examined is associated with the special 
male scales, which are in some cases distributed more or less 
generally over the wing in the shape of the ‘battledore scales’ 
of Lycenids, and the ‘plumules’ of many Pierines, Satyrids 
and Nymphalis, and in other cases collected into the definite 
areas called variously ‘chalky patches,’ ‘sex-brands’ or 
‘glandular spots.’ The proof of this is that scales removed 
from the wing are found to possess the odour strongly, 
provided that the special scales are present; the absence of 
special scales means the absence of scent. In Colias edusa, 
where the special scales are segregated, I obtained direct proof 
that the odour present in them was absent from the rest. The 
wings after being well rubbed retain little or no scent, nor 
does any appear to attach to the body. I reserve the case of 
G. rhamni, which has neither plumules nor circumscribed 
scent-patches, for later treatment. 
“Though the special scent-scales seem to act as reservoirs 
and distributors of the perfume, they are not the seat of its 
manufacture. This is doubtless carried on by certain secreting 
cells, described and figured by Giinther, which are found in 
connection with the sockets of the scent-scales, lying between 
the two layers of the wing-membrane. I have been investi- 
gating the structure of the scent-distributing apparatus in 
Pierines for some years past, and hope soon to be able to 
communicate my results, together with some account of the 
literature of the subject, which, though large, is scattered and 
by no means exhaustive. 
“7 may mention, in conclusion, that I have made several 
attempts to preserve the scent of various male butterflies, with 
more or less success. The first method I tried was extracting 
the wings with rectified spirit. This certainly took up the 
odour to some extent, but unless one uses the extract in a very 
concentrated form, the characteristic scent, which is seldom 
strong, is liable to be overpowered by the proper smell of the 
spirit. I then tried rubbing up the wings in a mortar with 
starch, choosing this as a practically odourless substance. In 
